A stringed musical instrument such as a guitar is typically protected from damage during storage or transport by a hard or soft case that encloses the entire instrument. Such traditional cases do not necessarily protect the instrument from being jarred out of tune. The tuning keys of the instrument, protruding from one or both sides of the instrument's head or headstock, are at risk from inadvertent physical contact. This contact can occur with the interior walls of a loosely fitting hard instrument case, the fabric of a soft instrument cover as it is being pulled over the instrument, or objects in the immediate environment that contact the tuning keys either directly or through a soft cover. Physical contact with the knobs of the tuning keys can cause them turn slightly, changing the pitch of the instrument's strings.
A hard instrument case may be able to protect the tuning keys from movement, but only if the interior of the case is custom-fitted to the particular dimensions of the instrument. A custom-made hard case of this type is relatively expensive, bulky and heavy. This type of protection is not even possible with a soft instrument cover. Thus, it would be highly desirable to have a protective cover for a stringed musical instrument that encloses the tuning keys and is secured against the instrument's headstock to prevent either the cover itself or any other object from contacting the knobs of the tuning keys.